Liposarcoma is a rare type of cancer that begins in the fat cells. Liposarcoma is considered a type of soft tissue sarcoma. Liposarcoma can occur in fat cells in any part of the body, but most cases occur in the muscles of the limbs or in the abdomen. Liposarcoma occurs most often in older adults, though it can occur at any age. Treatment for liposarcoma typically involves surgery to remove cancer. Other treatments, such as radiation therapy, also may be used.